Inkjet printing is a technology that uses drops of ink to form an image on a print medium, such as paper. According to some implementations, drops of ink are fired through nozzles formed in a printhead.
In many inkjet applications, such as thermal inkjet applications the temperatures within the print cartridge vary during operation. For example, at printer startup, the printhead temperature is typically below a normal operating temperature. The printhead temperature then tends to increase as the associated printer warms up and printing occurs.
As the temperature of a printhead varies, the drop volume (i.e., the amount of ink ejected from a printhead nozzle) also tends to vary. For example, as the temperature of a printhead increases, the drop volume of the ink ejected from the printhead tends to increase. Likewise, as the temperature of the printhead decreases, the drop volume of the ink ejected from the printhead also tends to decrease.
This temperature-dependent variation in drop volume may adversely affect the quality of a printed image. For example, drop volumes that are too small may result in streaking. Conversely, drop volumes that are too large may increase drop drying times, paper cockle, or both. Variation in drop sizes across a print or from print to print may also cause undesirable hue shifts, in some applications. For these and other reasons, there is a need for the present print cartridge temperature control.
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